Bright light therapy for bipolar depression

Bright light therapy (BLT) refers to the use of bright light to treat symptoms of depression. BLT was initially prescribed as a treatment for patients with seasonal affective disorder.1 It was later found helpful for nonseasonal depression,2 premenstrual dysphoric disorder, postpartum depression, and phase shift circadian disorders, including for patients with dementia whose cognitive function improved after treatment with BLT.3 More recent studies suggest year-round benefit for nonseasonal depression.2 The American Psychiatric Association practice guidelines for the treatment of depression list BLT as an alternative and/or addition to pharmacologic and psychological treatment.4 BLT also may be beneficial for patients who are in the depressive phase of bipolar illness.